Driving mechanism for motors and rotary piston pumps



Jan. 27, 1925. 1,524,447

P. MOLINARI DRIVING MECHANISM FOR MOTORS AND ROTARY PISTON IPUMPS Filed Aug. 25, 1923 Patented Jan. 27, i925.

UNITED STATES PAOLO MOLINARI, OF TARANTO, ITALY.

DRIVING MECHANISM FOR MOTGRS AND ROTARY PISTON PUMPS Application led August 25, 1923. Serial No. 659,302.

To all whom t may concern.'

Be it known that I, PAoLo MoLiNARI, a subject of the King of Italy, and residing at 42 Via de Cesare, Taranto, Italy, havev invented certain new and useful Improvements in Driving Mechanism for Motors and Rotary Piston Pumps, of which the Vfollowing is a specification.

The invention relates to improvements in driving mechanism for motors and rotary piston pumps.

The invention will hereafter be described with reference to a pump, but it is evident that it might equally well be applied to motors if the driving fluid is made to enter through the delivery pipes and is discharged through the suction pipes, or vice versa.

In the drawings which refer to a'small hand-drivenpump of a capacity of about 2500 tons per hours,

Figure 1 shows on lthe left hand side a sectional elevation on line B-B of Figure 2 and on the right hand side an outside view of the pump,

Figure 2 is a sectional plan view on line- Figure 3 is an outside View of the cover plate with the boss member,

Figure 4 isa sectional elevation thereof.

The pump comprises a vcircular dishshaped plate 1 which .at its center forms a hub with a tapered bore for the passage of the driving shaft 2. In Figure 1 the driving shaft is shown as having a square upper end to attach thereto a hand-wheel for the operation of the pump, but it isl evident that it might also have acylindrical upper end for connecting it with a motor or the like. rIhe plate 1 is rigidly connected to shaft 2 by means of a key 3, a nut 4 engaging a threaded portion of the shaft and held in place by a stop pin, and a clamping ring 5 lodgedv between the circular pla-te and a shoulder atA the lower end of the shaft.

The circular plate 1 has secured to it by means of countersunk screws 6 a cylinder 7 provided on its inner surface with teeth. These teeth are interrupted by three large teeth 8 spaced apart by 120 and hereafter referred to as suction and delivery teeth. On the top of the gear cylinder 7 is secured by countersunk screws a ring 9.

The circular plate 1, the gea-r cylinder 7 and the ring 9 are assembled to form one single unit and in pumps of larger dimensions they may be held together by tap bolts or studs.

1Within the gear cylinder 7 are arranged two pinions 10 which revolve on stationary spindles 11, these spindles being squareshaped at their lower end and projecting fromA the respective pinion. Each pinion is provided with a semi-cylindrical recess to receive the suction and delivery teeth 8 as will hereafter be explained.

The whole device is covered by a cover plate 12 which is traversed centrally by the driving shaft 2. Formed integrally with this cover plate is a downwardly projecting ring-shaped hollow boss member 13, on whose outer cylindrical wall the ring 9 and the suction and delivery teeth 8 are arranged to slide. This boss 13 is provided with two semi-cylindrical recesses adapted to accommodate the pinions 10.

The hollow boss 13 is divided into four chambers, two 14, 14 for suction purposes and two 15, 15 for delivery purposes, and each of these chambers communicates with a nozzle on the'cover plate to which are attached the'respective pipes. Each chamber is put in communication with the' sectorshaped hollows formed between the gear cylinder 7 and the sliding surface of the boss 13, by means of three tapered squarew shaped ports provided in the sliding sur face adjacent the pinions, these ports being indicated by 16, 16', 16, 16 in the drawing.

The square-shaped lower ends of the spindles 11 are seated in a circular plate 17 embedded in the plate 1 and secured by means ofl countersunk screws to the boss member 13, whereas their upper cylindrical ends are seated in the cover plate 12.

The plate 17 serves also as a cover for the suction and delivery chambers and as a division between these chambers. The whole device is enclosed within an outer casing 18 secured to the cover plate 12 by means of bolts or set screws and provided with lugs for securing the pump to a support.

The ring 9 is formed with an upwardly projecting rim 19 which engages a circular groove provided in the cover 12, for the purpose 0f aording an additional security against leakages between the ring 9 and the boss member 13. In a like manner a downwardly extending circular projection 2O is provided on the plat-e 17 and engages a llO . teeth andthe recesseswithin the pinions areshapedfso that during the rotation of thegear cylinderthe tooth adjacent the recessin thepnion remains .for a short -period in contact with the respective suction andv delivery tooth, in ordei1 to'prevent leakagesbetweenkthe hollows when the pinions areno longerill-engagement with the smaller.V teeth of the gear'eylinder. IIowever,.the teeth ofthe gearr cylinder which are arranged symmetrically respecting the1 suction and: delivery :.teeth, might `also extend close up to the lianlrsof ftheselargeteeth, so that .at the entrance .of these .teeth into .the recess-of the pinions the. teeth ofthese pinions will always be in nieshovitli'tlie teeth.

of; thev .gear cylinder.

TheA pump works. as follows :l

During vthe rotation `.of the .driving .shaft .2v and of the-.gear cylinder7 in the. direc- .tionof the arrow (Fig...2) the suction and deliveryfteeth whichslid'e .on the outer surface of the boss 13, .set up onone side: a Sucking action ,and thusf cause vliquid to .iow through the lportsinto thecylindrical hol- -lowsywhile .on the other. side. they .produce a. compression. of the Yliquid sucked up-'by thehpreceding `Vtooth so as `to cause-the liquid being driven into the respective delivery pipe. During. .the vrotation of the .gear cylinder 7a rotary motion isimparted to the'.,;pinions :10 through -the teeth ofthese two .parts'being 'in mesh, and the arrangement isgsuch thatthe pinions will 'complete their revolution .and their recess be brought opposite thegear. cylinder whenrthe suction` and Ydelivery teeth kare approaching the pinions n To Vprovide :tor the .discharge` of the liquidcaught -in -thespace between the vsuction andfdelivery teeth and thepinionsfat the moment Awhen these teeth 1 are closing :the

ports and are about to enter the respective recess .`in-.the .pinions, therey are provided grooves-.122.fonithelwall ofthe recessin the vboss .13 towards e the ports and small. holes v23;'are providedat the end V.of the edgel of thefrecess in Vpinions 10,' these. .holes and grooveswbemg; shaped and arranged so .that

thereeremains a.-sulieient-lclearance between therrthnd the edges.` ofgthesuction.- andv det l livery teeth. The holes might be replaced by :grooves formed on the projecting edgts of the recesses in the pinions.

In order to permit the escape of any liquid that may be caught between the teeth of the pinions and those of the gear cylinder 7, these pinions are slightly tapered, as indicated in 24, along a line whose length is almost equal to the depth of the teeth, and this taper corresponds to alike taper in the semi-cylindrical recesses oit the boss member 13.

Toavoid a suction and'a delivery cha-mber being put in conmulnication through u sector-shaped hollow,- the suction and delivery teeth and the ports are so dimensioned that when a Atooth is about toA un- .cover the delivery port of a hollow the sec cessive tooth will already have covered the corresponding suction part.

In motors and pumps which mustl deliver at a high pressure, blade springs...25and plates 26 may be` arranged inside each suction and delivery tooth to assure the "required contact between the. teeth and the wall of the boss member 13.' The length of the springs is: equal to the width of the teeth, while the plates 26 fprojectsli htly at one end into the ring 9 and at. the otv ier end into the plate 1,1whereby displacements of these plates are'.prevented during the passage of the suction'l and delivery. teeth through the recesses in the pinions.

In pumps whichwork at a -higlr pressure it is advisable to balance at least partly the pressure to which the pinions are subjected in the semi-cylindricalrecesses inthe boss member 13 and for thispurpose small clearances 27, 27 maybe .provided which by means of channelsz28g'28" communicate with the delivery chambers. The pump may thus rotate in either direction and the .suction and delivery actionsbeinverted.

Instead of projecting .through the cover 12 the` shaft 2 might alsobe made to pass through the casing 18,` in which case the taper of the /hub would of course be inverted.

In the case of pumps of large dimensions the boss member -13 may be formed rseparately and be secured to the cover 12 by mea-ns of studs and nuts and in this casethe plate 17 may be cast in `one piece. with fthe boss member 13.

The central wall of the boss member 13 around the drivingshaft, the suction and delivery chambers and the outside wall of the gear cylinder may be .provided with collarsy of zinc or the like and with protective plates incase the pump is to work with salt water. Ball bearings may be arranged' both on the driving shaft and beneath the circular plate 1 and the spindles of the pinions may be drilled centrally to permit lubrification by means oflu'briticators arranged on the cover.

Further, in the case of pumps working at a high pressure, in order to keep the plate l balanced, holes may be provided therein opposite the plate 17 so that the pressure eventually set up between the plates will be balanced by the pressure between the plate l and the casing.

'What I claim is:

l. In a driving means for motors or rotary piston pumps, a driving shaft, a gear operated thereby, suction and delivery teeth formed on the gear, a hollow boss having a cylindrical surface for cooperation with the suction and delivery teeth, springs and plates carried by said suction and delivery teeth to prevent leakage between said teeth and (he sliding surface, the hollow boss member heilig formed with two suction and two delivery chambers communicating' with sectorshaped hollows formed between the gear cylinder and the sliding surface of the boss.

2. In a driving means for motors or rotary piston pumps, a driving shaft, a gear operated thereby, suction and delivery teeth formed on the gear, a hollow boss having a cylindrical surface for cooperation with the suction and delivery teeth, springs and plates carried by said suction and delivery teeth to prevent leakage between said teeth and the sliding surface, the hollow boss member being formed with two suction and two delivery chambers communicating with sector-shaped hollows formed between the gear cylinder and the sliding surface of the boss,

and connections between said hollows and delivery chambers to permit reverse action o-f the pump.

In testimony whereof I have signed at Messina this 6th: day of August, 1923, in the presence of two subscribing witnesses.

PAULO MOLINARI.,

Witnesses:

CARLO SOLLIMAN Dormi, CRESCENHIO P. PRIMA. 

